BitWithBite
Biology Worksheet
🌱 Mendelian Genetics
SCORE___ / 20
NameClassDate
After this worksheet you can
State Mendel's two lawsSolve a Punnett squareDetermine blood typesDistinguish inheritance patterns📚 Quick Recap
🎯 What you'll practice: Mendel's laws, monohybrid/dihybrid ratios, and codominance/incomplete dominance/sex-linkage.
🧠 Section A · Concept Check ● BEGINNER 4 × 1 = 4
1Aa × Aa gives a phenotype ratio of:
2Blood type AB is an example of:
3Colour blindness is inherited as:
4Genotype IAi has blood type:
🧮 Section B · Problem Solving ● INTERMEDIATE 2 + 3×3 = 11
5A dihybrid cross gives a phenotypic ratio.
6Red + white flowers giving pink offspring is dominance.
7Draw the Punnett square for Aa × Aa and state the genotype ratio.
8A test cross is Aa × aa. What phenotype ratio results?
9What blood type results from ii genotype?
🚀 Section C · Challenge ● CHALLENGE 5
10A colour-blind son is born to a mother with normal vision and a colour-blind father. Explain how this is possible given X-linked recessive inheritance, and state the mother's most likely genotype.
💭 Reflection — the most useful thing I learned:
A ___/4 B ___/11 C ___/5 Total ___/20
Teacher's Signature
Parent's Signature
✂ answer key — fold or cut before handing out
1-B 2-B 3-C 4-A | 5 = 9:3:3:1 6 = incomplete 7 = AA : Aa : Aa : aa → genotype ratio 1:2:1 8 = 1:1 (Aa : aa) 9 = Type O | 10 = Since colour blindness is X-linked recessive, a colour-blind son (genotype XᶜY) must have inherited his single X chromosome, carrying the recessive allele, from his mother — the father's X chromosome does not pass to sons at all (sons get the father's Y). This means the mother must be a carrier, genotype XᶜX (heterozygous), passing the recessive Xᶜ to her son while her own normal vision is explained by her other, dominant X allele masking it.